2005-04-17 06:20:36 +08:00
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/*
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* linux/fs/minix/inode.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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2009-03-22 06:18:57 +08:00
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* Copyright (C) 1996 Gertjan van Wingerde
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2005-04-17 06:20:36 +08:00
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* Minix V2 fs support.
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*
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* Modified for 680x0 by Andreas Schwab
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2007-02-12 16:52:49 +08:00
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* Updated to filesystem version 3 by Daniel Aragones
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2005-04-17 06:20:36 +08:00
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*/
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#include <linux/module.h>
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#include "minix.h"
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#include <linux/buffer_head.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/highuid.h>
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#include <linux/vfs.h>
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2010-03-05 16:21:37 +08:00
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#include <linux/writeback.h>
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2005-04-17 06:20:36 +08:00
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2010-03-05 16:21:37 +08:00
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static int minix_write_inode(struct inode *inode,
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struct writeback_control *wbc);
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2006-06-23 17:02:58 +08:00
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static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
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2005-04-17 06:20:36 +08:00
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static int minix_remount (struct super_block * sb, int * flags, char * data);
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2010-06-05 10:27:38 +08:00
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static void minix_evict_inode(struct inode *inode)
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2005-04-17 06:20:36 +08:00
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{
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2014-04-04 05:47:49 +08:00
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truncate_inode_pages_final(&inode->i_data);
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2010-06-05 10:27:38 +08:00
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if (!inode->i_nlink) {
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inode->i_size = 0;
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minix_truncate(inode);
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}
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invalidate_inode_buffers(inode);
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2012-05-03 20:48:02 +08:00
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clear_inode(inode);
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2010-06-05 10:27:38 +08:00
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if (!inode->i_nlink)
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minix_free_inode(inode);
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2005-04-17 06:20:36 +08:00
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}
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static void minix_put_super(struct super_block *sb)
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{
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int i;
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struct minix_sb_info *sbi = minix_sb(sb);
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2017-07-17 15:45:34 +08:00
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if (!sb_rdonly(sb)) {
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2007-02-12 16:52:49 +08:00
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if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
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sbi->s_ms->s_state = sbi->s_mount_state;
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2005-04-17 06:20:36 +08:00
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mark_buffer_dirty(sbi->s_sbh);
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}
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for (i = 0; i < sbi->s_imap_blocks; i++)
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brelse(sbi->s_imap[i]);
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for (i = 0; i < sbi->s_zmap_blocks; i++)
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brelse(sbi->s_zmap[i]);
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brelse (sbi->s_sbh);
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kfree(sbi->s_imap);
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sb->s_fs_info = NULL;
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kfree(sbi);
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}
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2006-12-07 12:33:20 +08:00
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static struct kmem_cache * minix_inode_cachep;
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2005-04-17 06:20:36 +08:00
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static struct inode *minix_alloc_inode(struct super_block *sb)
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{
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struct minix_inode_info *ei;
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2015-06-26 06:03:40 +08:00
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ei = kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
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2005-04-17 06:20:36 +08:00
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if (!ei)
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return NULL;
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return &ei->vfs_inode;
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}
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2011-01-07 14:49:49 +08:00
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static void minix_i_callback(struct rcu_head *head)
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2005-04-17 06:20:36 +08:00
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{
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2011-01-07 14:49:49 +08:00
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struct inode *inode = container_of(head, struct inode, i_rcu);
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2005-04-17 06:20:36 +08:00
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kmem_cache_free(minix_inode_cachep, minix_i(inode));
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}
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2011-01-07 14:49:49 +08:00
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static void minix_destroy_inode(struct inode *inode)
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{
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call_rcu(&inode->i_rcu, minix_i_callback);
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}
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2008-07-26 10:45:34 +08:00
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static void init_once(void *foo)
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2005-04-17 06:20:36 +08:00
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{
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struct minix_inode_info *ei = (struct minix_inode_info *) foo;
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2007-05-17 13:10:57 +08:00
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inode_init_once(&ei->vfs_inode);
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2005-04-17 06:20:36 +08:00
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}
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2007-07-20 09:11:58 +08:00
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2014-04-04 05:50:21 +08:00
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static int __init init_inodecache(void)
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2005-04-17 06:20:36 +08:00
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{
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minix_inode_cachep = kmem_cache_create("minix_inode_cache",
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sizeof(struct minix_inode_info),
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2006-03-24 19:16:06 +08:00
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0, (SLAB_RECLAIM_ACCOUNT|
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2016-01-15 07:18:21 +08:00
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SLAB_MEM_SPREAD|SLAB_ACCOUNT),
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2007-07-20 09:11:58 +08:00
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init_once);
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2005-04-17 06:20:36 +08:00
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if (minix_inode_cachep == NULL)
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return -ENOMEM;
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return 0;
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}
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static void destroy_inodecache(void)
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{
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2012-09-26 09:33:07 +08:00
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/*
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* Make sure all delayed rcu free inodes are flushed before we
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* destroy cache.
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*/
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rcu_barrier();
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2006-09-27 16:49:40 +08:00
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kmem_cache_destroy(minix_inode_cachep);
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2005-04-17 06:20:36 +08:00
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}
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2007-02-12 16:55:41 +08:00
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static const struct super_operations minix_sops = {
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2005-04-17 06:20:36 +08:00
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.alloc_inode = minix_alloc_inode,
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.destroy_inode = minix_destroy_inode,
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.write_inode = minix_write_inode,
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2010-06-05 10:27:38 +08:00
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.evict_inode = minix_evict_inode,
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2005-04-17 06:20:36 +08:00
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.put_super = minix_put_super,
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.statfs = minix_statfs,
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.remount_fs = minix_remount,
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};
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static int minix_remount (struct super_block * sb, int * flags, char * data)
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{
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struct minix_sb_info * sbi = minix_sb(sb);
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struct minix_super_block * ms;
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2014-03-13 22:14:33 +08:00
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sync_filesystem(sb);
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2005-04-17 06:20:36 +08:00
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ms = sbi->s_ms;
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2017-07-17 15:45:34 +08:00
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if ((bool)(*flags & MS_RDONLY) == sb_rdonly(sb))
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2005-04-17 06:20:36 +08:00
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return 0;
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if (*flags & MS_RDONLY) {
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if (ms->s_state & MINIX_VALID_FS ||
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!(sbi->s_mount_state & MINIX_VALID_FS))
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return 0;
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/* Mounting a rw partition read-only. */
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2007-02-12 16:52:49 +08:00
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if (sbi->s_version != MINIX_V3)
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ms->s_state = sbi->s_mount_state;
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2005-04-17 06:20:36 +08:00
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mark_buffer_dirty(sbi->s_sbh);
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} else {
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/* Mount a partition which is read-only, read-write. */
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2007-02-12 16:52:49 +08:00
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if (sbi->s_version != MINIX_V3) {
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sbi->s_mount_state = ms->s_state;
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ms->s_state &= ~MINIX_VALID_FS;
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} else {
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sbi->s_mount_state = MINIX_VALID_FS;
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}
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2005-04-17 06:20:36 +08:00
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mark_buffer_dirty(sbi->s_sbh);
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if (!(sbi->s_mount_state & MINIX_VALID_FS))
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2006-03-25 19:07:42 +08:00
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printk("MINIX-fs warning: remounting unchecked fs, "
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"running fsck is recommended\n");
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2005-04-17 06:20:36 +08:00
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else if ((sbi->s_mount_state & MINIX_ERROR_FS))
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2006-03-25 19:07:42 +08:00
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printk("MINIX-fs warning: remounting fs with errors, "
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"running fsck is recommended\n");
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2005-04-17 06:20:36 +08:00
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}
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return 0;
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}
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static int minix_fill_super(struct super_block *s, void *data, int silent)
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{
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struct buffer_head *bh;
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struct buffer_head **map;
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struct minix_super_block *ms;
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2007-02-12 16:52:49 +08:00
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struct minix3_super_block *m3s = NULL;
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unsigned long i, block;
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2005-04-17 06:20:36 +08:00
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struct inode *root_inode;
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struct minix_sb_info *sbi;
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2008-02-07 16:15:44 +08:00
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int ret = -EINVAL;
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2005-04-17 06:20:36 +08:00
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2006-09-27 16:49:37 +08:00
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sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
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2005-04-17 06:20:36 +08:00
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if (!sbi)
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return -ENOMEM;
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s->s_fs_info = sbi;
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2006-10-11 16:22:05 +08:00
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BUILD_BUG_ON(32 != sizeof (struct minix_inode));
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BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
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2005-04-17 06:20:36 +08:00
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if (!sb_set_blocksize(s, BLOCK_SIZE))
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goto out_bad_hblock;
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if (!(bh = sb_bread(s, 1)))
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goto out_bad_sb;
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ms = (struct minix_super_block *) bh->b_data;
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sbi->s_ms = ms;
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sbi->s_sbh = bh;
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sbi->s_mount_state = ms->s_state;
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sbi->s_ninodes = ms->s_ninodes;
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sbi->s_nzones = ms->s_nzones;
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sbi->s_imap_blocks = ms->s_imap_blocks;
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sbi->s_zmap_blocks = ms->s_zmap_blocks;
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sbi->s_firstdatazone = ms->s_firstdatazone;
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sbi->s_log_zone_size = ms->s_log_zone_size;
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sbi->s_max_size = ms->s_max_size;
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s->s_magic = ms->s_magic;
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if (s->s_magic == MINIX_SUPER_MAGIC) {
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sbi->s_version = MINIX_V1;
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sbi->s_dirsize = 16;
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sbi->s_namelen = 14;
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2012-02-07 01:45:27 +08:00
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s->s_max_links = MINIX_LINK_MAX;
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2005-04-17 06:20:36 +08:00
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} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
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sbi->s_version = MINIX_V1;
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sbi->s_dirsize = 32;
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sbi->s_namelen = 30;
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2012-02-07 01:45:27 +08:00
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s->s_max_links = MINIX_LINK_MAX;
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2005-04-17 06:20:36 +08:00
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} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
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sbi->s_version = MINIX_V2;
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sbi->s_nzones = ms->s_zones;
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sbi->s_dirsize = 16;
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sbi->s_namelen = 14;
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2012-02-07 01:45:27 +08:00
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s->s_max_links = MINIX2_LINK_MAX;
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2005-04-17 06:20:36 +08:00
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} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
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sbi->s_version = MINIX_V2;
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sbi->s_nzones = ms->s_zones;
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sbi->s_dirsize = 32;
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sbi->s_namelen = 30;
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2012-02-07 01:45:27 +08:00
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s->s_max_links = MINIX2_LINK_MAX;
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2007-02-12 16:52:49 +08:00
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} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
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m3s = (struct minix3_super_block *) bh->b_data;
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s->s_magic = m3s->s_magic;
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sbi->s_imap_blocks = m3s->s_imap_blocks;
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sbi->s_zmap_blocks = m3s->s_zmap_blocks;
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sbi->s_firstdatazone = m3s->s_firstdatazone;
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sbi->s_log_zone_size = m3s->s_log_zone_size;
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sbi->s_max_size = m3s->s_max_size;
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sbi->s_ninodes = m3s->s_ninodes;
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sbi->s_nzones = m3s->s_zones;
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sbi->s_dirsize = 64;
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sbi->s_namelen = 60;
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sbi->s_version = MINIX_V3;
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sbi->s_mount_state = MINIX_VALID_FS;
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sb_set_blocksize(s, m3s->s_blocksize);
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2012-02-07 01:45:27 +08:00
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s->s_max_links = MINIX2_LINK_MAX;
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2005-04-17 06:20:36 +08:00
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} else
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goto out_no_fs;
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/*
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* Allocate the buffer map to keep the superblock small.
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*/
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2006-08-27 16:23:42 +08:00
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if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
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goto out_illegal_sb;
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2005-04-17 06:20:36 +08:00
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i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
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2006-09-27 16:49:37 +08:00
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map = kzalloc(i, GFP_KERNEL);
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2005-04-17 06:20:36 +08:00
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if (!map)
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goto out_no_map;
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sbi->s_imap = &map[0];
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sbi->s_zmap = &map[sbi->s_imap_blocks];
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block=2;
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for (i=0 ; i < sbi->s_imap_blocks ; i++) {
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if (!(sbi->s_imap[i]=sb_bread(s, block)))
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goto out_no_bitmap;
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block++;
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}
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for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
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if (!(sbi->s_zmap[i]=sb_bread(s, block)))
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goto out_no_bitmap;
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block++;
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}
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minix_set_bit(0,sbi->s_imap[0]->b_data);
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minix_set_bit(0,sbi->s_zmap[0]->b_data);
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|
2011-08-20 02:50:26 +08:00
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/* Apparently minix can create filesystems that allocate more blocks for
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* the bitmaps than needed. We simply ignore that, but verify it didn't
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* create one with not enough blocks and bail out if so.
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*/
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block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
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if (sbi->s_imap_blocks < block) {
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printk("MINIX-fs: file system does not have enough "
|
2014-08-09 05:20:29 +08:00
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"imap blocks allocated. Refusing to mount.\n");
|
2012-02-13 11:07:43 +08:00
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goto out_no_bitmap;
|
2011-08-20 02:50:26 +08:00
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}
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block = minix_blocks_needed(
|
2014-08-09 05:20:29 +08:00
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(sbi->s_nzones - sbi->s_firstdatazone + 1),
|
2011-08-20 02:50:26 +08:00
|
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s->s_blocksize);
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if (sbi->s_zmap_blocks < block) {
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printk("MINIX-fs: file system does not have enough "
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|
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"zmap blocks allocated. Refusing to mount.\n");
|
2012-02-13 11:07:43 +08:00
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goto out_no_bitmap;
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}
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|
|
/* set up enough so that it can read an inode */
|
|
|
|
s->s_op = &minix_sops;
|
|
|
|
root_inode = minix_iget(s, MINIX_ROOT_INO);
|
|
|
|
if (IS_ERR(root_inode)) {
|
|
|
|
ret = PTR_ERR(root_inode);
|
|
|
|
goto out_no_root;
|
2011-08-20 02:50:26 +08:00
|
|
|
}
|
|
|
|
|
2012-01-04 18:51:03 +08:00
|
|
|
ret = -ENOMEM;
|
2012-02-13 11:07:43 +08:00
|
|
|
s->s_root = d_make_root(root_inode);
|
2012-01-04 18:51:03 +08:00
|
|
|
if (!s->s_root)
|
2012-02-13 11:07:43 +08:00
|
|
|
goto out_no_root;
|
2012-01-04 18:51:03 +08:00
|
|
|
|
2017-07-17 15:45:34 +08:00
|
|
|
if (!sb_rdonly(s)) {
|
2012-01-04 18:51:03 +08:00
|
|
|
if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
|
|
|
|
ms->s_state &= ~MINIX_VALID_FS;
|
|
|
|
mark_buffer_dirty(bh);
|
|
|
|
}
|
|
|
|
if (!(sbi->s_mount_state & MINIX_VALID_FS))
|
|
|
|
printk("MINIX-fs: mounting unchecked file system, "
|
|
|
|
"running fsck is recommended\n");
|
|
|
|
else if (sbi->s_mount_state & MINIX_ERROR_FS)
|
|
|
|
printk("MINIX-fs: mounting file system with errors, "
|
|
|
|
"running fsck is recommended\n");
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
out_no_root:
|
|
|
|
if (!silent)
|
|
|
|
printk("MINIX-fs: get root inode failed\n");
|
|
|
|
goto out_freemap;
|
|
|
|
|
|
|
|
out_no_bitmap:
|
|
|
|
printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
|
2006-08-27 16:23:42 +08:00
|
|
|
out_freemap:
|
2005-04-17 06:20:36 +08:00
|
|
|
for (i = 0; i < sbi->s_imap_blocks; i++)
|
|
|
|
brelse(sbi->s_imap[i]);
|
|
|
|
for (i = 0; i < sbi->s_zmap_blocks; i++)
|
|
|
|
brelse(sbi->s_zmap[i]);
|
|
|
|
kfree(sbi->s_imap);
|
|
|
|
goto out_release;
|
|
|
|
|
|
|
|
out_no_map:
|
2008-02-07 16:15:44 +08:00
|
|
|
ret = -ENOMEM;
|
2005-04-17 06:20:36 +08:00
|
|
|
if (!silent)
|
2006-03-25 19:07:42 +08:00
|
|
|
printk("MINIX-fs: can't allocate map\n");
|
2005-04-17 06:20:36 +08:00
|
|
|
goto out_release;
|
|
|
|
|
2006-08-27 16:23:42 +08:00
|
|
|
out_illegal_sb:
|
|
|
|
if (!silent)
|
|
|
|
printk("MINIX-fs: bad superblock\n");
|
|
|
|
goto out_release;
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
out_no_fs:
|
|
|
|
if (!silent)
|
2007-02-12 16:52:49 +08:00
|
|
|
printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
|
|
|
|
"on device %s.\n", s->s_id);
|
2006-08-27 16:23:42 +08:00
|
|
|
out_release:
|
2005-04-17 06:20:36 +08:00
|
|
|
brelse(bh);
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
out_bad_hblock:
|
2006-03-25 19:07:42 +08:00
|
|
|
printk("MINIX-fs: blocksize too small for device\n");
|
2005-04-17 06:20:36 +08:00
|
|
|
goto out;
|
|
|
|
|
|
|
|
out_bad_sb:
|
|
|
|
printk("MINIX-fs: unable to read superblock\n");
|
2006-08-27 16:23:42 +08:00
|
|
|
out:
|
2005-04-17 06:20:36 +08:00
|
|
|
s->s_fs_info = NULL;
|
|
|
|
kfree(sbi);
|
2008-02-07 16:15:44 +08:00
|
|
|
return ret;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
2006-06-23 17:02:58 +08:00
|
|
|
static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2009-04-03 07:59:39 +08:00
|
|
|
struct super_block *sb = dentry->d_sb;
|
|
|
|
struct minix_sb_info *sbi = minix_sb(sb);
|
|
|
|
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
|
|
|
|
buf->f_type = sb->s_magic;
|
|
|
|
buf->f_bsize = sb->s_blocksize;
|
2005-04-17 06:20:36 +08:00
|
|
|
buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
|
2011-08-20 02:50:26 +08:00
|
|
|
buf->f_bfree = minix_count_free_blocks(sb);
|
2005-04-17 06:20:36 +08:00
|
|
|
buf->f_bavail = buf->f_bfree;
|
|
|
|
buf->f_files = sbi->s_ninodes;
|
2011-08-20 02:50:26 +08:00
|
|
|
buf->f_ffree = minix_count_free_inodes(sb);
|
2005-04-17 06:20:36 +08:00
|
|
|
buf->f_namelen = sbi->s_namelen;
|
2009-04-03 07:59:39 +08:00
|
|
|
buf->f_fsid.val[0] = (u32)id;
|
|
|
|
buf->f_fsid.val[1] = (u32)(id >> 32);
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int minix_get_block(struct inode *inode, sector_t block,
|
|
|
|
struct buffer_head *bh_result, int create)
|
|
|
|
{
|
|
|
|
if (INODE_VERSION(inode) == MINIX_V1)
|
|
|
|
return V1_minix_get_block(inode, block, bh_result, create);
|
|
|
|
else
|
|
|
|
return V2_minix_get_block(inode, block, bh_result, create);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int minix_writepage(struct page *page, struct writeback_control *wbc)
|
|
|
|
{
|
|
|
|
return block_write_full_page(page, minix_get_block, wbc);
|
|
|
|
}
|
2007-10-16 16:25:21 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
static int minix_readpage(struct file *file, struct page *page)
|
|
|
|
{
|
|
|
|
return block_read_full_page(page,minix_get_block);
|
|
|
|
}
|
2007-10-16 16:25:21 +08:00
|
|
|
|
2010-06-04 17:29:56 +08:00
|
|
|
int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2010-06-04 17:29:57 +08:00
|
|
|
return __block_write_begin(page, pos, len, minix_get_block);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2007-10-16 16:25:21 +08:00
|
|
|
|
2012-12-15 18:56:25 +08:00
|
|
|
static void minix_write_failed(struct address_space *mapping, loff_t to)
|
|
|
|
{
|
|
|
|
struct inode *inode = mapping->host;
|
|
|
|
|
|
|
|
if (to > inode->i_size) {
|
2013-09-13 06:13:56 +08:00
|
|
|
truncate_pagecache(inode, inode->i_size);
|
2012-12-15 18:56:25 +08:00
|
|
|
minix_truncate(inode);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2007-10-16 16:25:21 +08:00
|
|
|
static int minix_write_begin(struct file *file, struct address_space *mapping,
|
|
|
|
loff_t pos, unsigned len, unsigned flags,
|
|
|
|
struct page **pagep, void **fsdata)
|
|
|
|
{
|
2010-06-04 17:29:58 +08:00
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = block_write_begin(mapping, pos, len, flags, pagep,
|
2010-06-04 17:29:56 +08:00
|
|
|
minix_get_block);
|
2012-12-15 18:56:25 +08:00
|
|
|
if (unlikely(ret))
|
|
|
|
minix_write_failed(mapping, pos + len);
|
2010-06-04 17:29:58 +08:00
|
|
|
|
|
|
|
return ret;
|
2007-10-16 16:25:21 +08:00
|
|
|
}
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
static sector_t minix_bmap(struct address_space *mapping, sector_t block)
|
|
|
|
{
|
|
|
|
return generic_block_bmap(mapping,block,minix_get_block);
|
|
|
|
}
|
2007-10-16 16:25:21 +08:00
|
|
|
|
2006-06-28 19:26:44 +08:00
|
|
|
static const struct address_space_operations minix_aops = {
|
2005-04-17 06:20:36 +08:00
|
|
|
.readpage = minix_readpage,
|
|
|
|
.writepage = minix_writepage,
|
2007-10-16 16:25:21 +08:00
|
|
|
.write_begin = minix_write_begin,
|
|
|
|
.write_end = generic_write_end,
|
2005-04-17 06:20:36 +08:00
|
|
|
.bmap = minix_bmap
|
|
|
|
};
|
|
|
|
|
2007-02-12 16:55:39 +08:00
|
|
|
static const struct inode_operations minix_symlink_inode_operations = {
|
2015-11-17 23:20:54 +08:00
|
|
|
.get_link = page_get_link,
|
2005-04-17 06:20:36 +08:00
|
|
|
.getattr = minix_getattr,
|
|
|
|
};
|
|
|
|
|
|
|
|
void minix_set_inode(struct inode *inode, dev_t rdev)
|
|
|
|
{
|
|
|
|
if (S_ISREG(inode->i_mode)) {
|
|
|
|
inode->i_op = &minix_file_inode_operations;
|
|
|
|
inode->i_fop = &minix_file_operations;
|
|
|
|
inode->i_mapping->a_ops = &minix_aops;
|
|
|
|
} else if (S_ISDIR(inode->i_mode)) {
|
|
|
|
inode->i_op = &minix_dir_inode_operations;
|
|
|
|
inode->i_fop = &minix_dir_operations;
|
|
|
|
inode->i_mapping->a_ops = &minix_aops;
|
|
|
|
} else if (S_ISLNK(inode->i_mode)) {
|
|
|
|
inode->i_op = &minix_symlink_inode_operations;
|
2015-11-17 14:07:57 +08:00
|
|
|
inode_nohighmem(inode);
|
2005-04-17 06:20:36 +08:00
|
|
|
inode->i_mapping->a_ops = &minix_aops;
|
|
|
|
} else
|
|
|
|
init_special_inode(inode, inode->i_mode, rdev);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The minix V1 function to read an inode.
|
|
|
|
*/
|
2008-02-07 16:15:44 +08:00
|
|
|
static struct inode *V1_minix_iget(struct inode *inode)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
|
|
|
struct buffer_head * bh;
|
|
|
|
struct minix_inode * raw_inode;
|
|
|
|
struct minix_inode_info *minix_inode = minix_i(inode);
|
|
|
|
int i;
|
|
|
|
|
|
|
|
raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
|
|
|
|
if (!raw_inode) {
|
2008-02-07 16:15:44 +08:00
|
|
|
iget_failed(inode);
|
|
|
|
return ERR_PTR(-EIO);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
inode->i_mode = raw_inode->i_mode;
|
2012-02-11 03:45:03 +08:00
|
|
|
i_uid_write(inode, raw_inode->i_uid);
|
|
|
|
i_gid_write(inode, raw_inode->i_gid);
|
2011-10-28 20:13:29 +08:00
|
|
|
set_nlink(inode, raw_inode->i_nlinks);
|
2005-04-17 06:20:36 +08:00
|
|
|
inode->i_size = raw_inode->i_size;
|
|
|
|
inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
|
|
|
|
inode->i_mtime.tv_nsec = 0;
|
|
|
|
inode->i_atime.tv_nsec = 0;
|
|
|
|
inode->i_ctime.tv_nsec = 0;
|
2006-09-27 16:50:49 +08:00
|
|
|
inode->i_blocks = 0;
|
2005-04-17 06:20:36 +08:00
|
|
|
for (i = 0; i < 9; i++)
|
|
|
|
minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
|
|
|
|
minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
|
|
|
|
brelse(bh);
|
2008-02-07 16:15:44 +08:00
|
|
|
unlock_new_inode(inode);
|
|
|
|
return inode;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The minix V2 function to read an inode.
|
|
|
|
*/
|
2008-02-07 16:15:44 +08:00
|
|
|
static struct inode *V2_minix_iget(struct inode *inode)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
|
|
|
struct buffer_head * bh;
|
|
|
|
struct minix2_inode * raw_inode;
|
|
|
|
struct minix_inode_info *minix_inode = minix_i(inode);
|
|
|
|
int i;
|
|
|
|
|
|
|
|
raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
|
|
|
|
if (!raw_inode) {
|
2008-02-07 16:15:44 +08:00
|
|
|
iget_failed(inode);
|
|
|
|
return ERR_PTR(-EIO);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
inode->i_mode = raw_inode->i_mode;
|
2012-02-11 03:45:03 +08:00
|
|
|
i_uid_write(inode, raw_inode->i_uid);
|
|
|
|
i_gid_write(inode, raw_inode->i_gid);
|
2011-10-28 20:13:29 +08:00
|
|
|
set_nlink(inode, raw_inode->i_nlinks);
|
2005-04-17 06:20:36 +08:00
|
|
|
inode->i_size = raw_inode->i_size;
|
|
|
|
inode->i_mtime.tv_sec = raw_inode->i_mtime;
|
|
|
|
inode->i_atime.tv_sec = raw_inode->i_atime;
|
|
|
|
inode->i_ctime.tv_sec = raw_inode->i_ctime;
|
|
|
|
inode->i_mtime.tv_nsec = 0;
|
|
|
|
inode->i_atime.tv_nsec = 0;
|
|
|
|
inode->i_ctime.tv_nsec = 0;
|
2006-09-27 16:50:49 +08:00
|
|
|
inode->i_blocks = 0;
|
2005-04-17 06:20:36 +08:00
|
|
|
for (i = 0; i < 10; i++)
|
|
|
|
minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
|
|
|
|
minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
|
|
|
|
brelse(bh);
|
2008-02-07 16:15:44 +08:00
|
|
|
unlock_new_inode(inode);
|
|
|
|
return inode;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The global function to read an inode.
|
|
|
|
*/
|
2008-02-07 16:15:44 +08:00
|
|
|
struct inode *minix_iget(struct super_block *sb, unsigned long ino)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2008-02-07 16:15:44 +08:00
|
|
|
struct inode *inode;
|
|
|
|
|
|
|
|
inode = iget_locked(sb, ino);
|
|
|
|
if (!inode)
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (!(inode->i_state & I_NEW))
|
|
|
|
return inode;
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
if (INODE_VERSION(inode) == MINIX_V1)
|
2008-02-07 16:15:44 +08:00
|
|
|
return V1_minix_iget(inode);
|
2005-04-17 06:20:36 +08:00
|
|
|
else
|
2008-02-07 16:15:44 +08:00
|
|
|
return V2_minix_iget(inode);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The minix V1 function to synchronize an inode.
|
|
|
|
*/
|
|
|
|
static struct buffer_head * V1_minix_update_inode(struct inode * inode)
|
|
|
|
{
|
|
|
|
struct buffer_head * bh;
|
|
|
|
struct minix_inode * raw_inode;
|
|
|
|
struct minix_inode_info *minix_inode = minix_i(inode);
|
|
|
|
int i;
|
|
|
|
|
|
|
|
raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
|
|
|
|
if (!raw_inode)
|
|
|
|
return NULL;
|
|
|
|
raw_inode->i_mode = inode->i_mode;
|
2012-02-11 03:45:03 +08:00
|
|
|
raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
|
|
|
|
raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
|
2005-04-17 06:20:36 +08:00
|
|
|
raw_inode->i_nlinks = inode->i_nlink;
|
|
|
|
raw_inode->i_size = inode->i_size;
|
|
|
|
raw_inode->i_time = inode->i_mtime.tv_sec;
|
|
|
|
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
|
|
|
|
raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
|
|
|
|
else for (i = 0; i < 9; i++)
|
|
|
|
raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
|
|
|
|
mark_buffer_dirty(bh);
|
|
|
|
return bh;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The minix V2 function to synchronize an inode.
|
|
|
|
*/
|
|
|
|
static struct buffer_head * V2_minix_update_inode(struct inode * inode)
|
|
|
|
{
|
|
|
|
struct buffer_head * bh;
|
|
|
|
struct minix2_inode * raw_inode;
|
|
|
|
struct minix_inode_info *minix_inode = minix_i(inode);
|
|
|
|
int i;
|
|
|
|
|
|
|
|
raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
|
|
|
|
if (!raw_inode)
|
|
|
|
return NULL;
|
|
|
|
raw_inode->i_mode = inode->i_mode;
|
2012-02-11 03:45:03 +08:00
|
|
|
raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
|
|
|
|
raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
|
2005-04-17 06:20:36 +08:00
|
|
|
raw_inode->i_nlinks = inode->i_nlink;
|
|
|
|
raw_inode->i_size = inode->i_size;
|
|
|
|
raw_inode->i_mtime = inode->i_mtime.tv_sec;
|
|
|
|
raw_inode->i_atime = inode->i_atime.tv_sec;
|
|
|
|
raw_inode->i_ctime = inode->i_ctime.tv_sec;
|
|
|
|
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
|
|
|
|
raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
|
|
|
|
else for (i = 0; i < 10; i++)
|
|
|
|
raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
|
|
|
|
mark_buffer_dirty(bh);
|
|
|
|
return bh;
|
|
|
|
}
|
|
|
|
|
2010-03-05 16:21:37 +08:00
|
|
|
static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
|
|
|
int err = 0;
|
|
|
|
struct buffer_head *bh;
|
|
|
|
|
2009-06-08 03:21:06 +08:00
|
|
|
if (INODE_VERSION(inode) == MINIX_V1)
|
|
|
|
bh = V1_minix_update_inode(inode);
|
|
|
|
else
|
|
|
|
bh = V2_minix_update_inode(inode);
|
|
|
|
if (!bh)
|
|
|
|
return -EIO;
|
2010-03-05 16:21:37 +08:00
|
|
|
if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
|
2005-04-17 06:20:36 +08:00
|
|
|
sync_dirty_buffer(bh);
|
2009-06-08 03:21:06 +08:00
|
|
|
if (buffer_req(bh) && !buffer_uptodate(bh)) {
|
2006-03-25 19:07:42 +08:00
|
|
|
printk("IO error syncing minix inode [%s:%08lx]\n",
|
2005-04-17 06:20:36 +08:00
|
|
|
inode->i_sb->s_id, inode->i_ino);
|
2009-06-08 03:21:06 +08:00
|
|
|
err = -EIO;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
brelse (bh);
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.
The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.
Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.
========
OVERVIEW
========
The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.
A number of requests were gathered for features to be included. The
following have been included:
(1) Make the fields a consistent size on all arches and make them large.
(2) Spare space, request flags and information flags are provided for
future expansion.
(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).
(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).
This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].
(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).
(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).
And the following have been left out for future extension:
(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].
Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.
(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).
(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].
(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].
(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).
(10) Extra coherency data may be useful in making backups [Andreas Dilger].
(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).
(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...
(This requires a separate system call - I have an fsinfo() call idea
for this).
(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].
(Deferred to fsinfo).
(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].
(Deferred to fsinfo).
(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).
(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).
(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].
(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).
(16) Femtosecond-resolution timestamps [Dave Chinner].
(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).
(17) A set multiple attributes syscall to go with this.
===============
NEW SYSTEM CALL
===============
The new system call is:
int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);
The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.
Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):
(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.
(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.
(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.
mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.
buffer points to the destination for the data. This must be 256 bytes in
size.
======================
MAIN ATTRIBUTES RECORD
======================
The following structures are defined in which to return the main attribute
set:
struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};
struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};
The defined bits in request_mask and stx_mask are:
STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]
stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.
Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.
The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:
STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs
Within the kernel, the supported flags are listed by:
KSTAT_ATTR_FS_IOC_FLAGS
[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]
New flags include:
STATX_ATTR_AUTOMOUNT Object is an automount trigger
These are for the use of GUI tools that might want to mark files specially,
depending on what they are.
Fields in struct statx come in a number of classes:
(0) stx_dev_*, stx_blksize.
These are local system information and are always available.
(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.
These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.
If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.
If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.
Note that there are instances where the type might not be valid, for
instance Windows reparse points.
(2) stx_rdev_*.
This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.
(3) stx_btime.
Similar to (1), except this will be set to 0 if it doesn't exist.
=======
TESTING
=======
The following test program can be used to test the statx system call:
samples/statx/test-statx.c
Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.
Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.
[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
Secondly, the result of automounting on that directory.
[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-02-01 00:46:22 +08:00
|
|
|
int minix_getattr(const struct path *path, struct kstat *stat,
|
|
|
|
u32 request_mask, unsigned int flags)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.
The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.
Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.
========
OVERVIEW
========
The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.
A number of requests were gathered for features to be included. The
following have been included:
(1) Make the fields a consistent size on all arches and make them large.
(2) Spare space, request flags and information flags are provided for
future expansion.
(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).
(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).
This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].
(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).
(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).
And the following have been left out for future extension:
(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].
Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.
(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).
(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].
(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].
(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).
(10) Extra coherency data may be useful in making backups [Andreas Dilger].
(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).
(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...
(This requires a separate system call - I have an fsinfo() call idea
for this).
(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].
(Deferred to fsinfo).
(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].
(Deferred to fsinfo).
(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).
(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).
(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].
(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).
(16) Femtosecond-resolution timestamps [Dave Chinner].
(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).
(17) A set multiple attributes syscall to go with this.
===============
NEW SYSTEM CALL
===============
The new system call is:
int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);
The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.
Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):
(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.
(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.
(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.
mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.
buffer points to the destination for the data. This must be 256 bytes in
size.
======================
MAIN ATTRIBUTES RECORD
======================
The following structures are defined in which to return the main attribute
set:
struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};
struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};
The defined bits in request_mask and stx_mask are:
STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]
stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.
Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.
The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:
STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs
Within the kernel, the supported flags are listed by:
KSTAT_ATTR_FS_IOC_FLAGS
[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]
New flags include:
STATX_ATTR_AUTOMOUNT Object is an automount trigger
These are for the use of GUI tools that might want to mark files specially,
depending on what they are.
Fields in struct statx come in a number of classes:
(0) stx_dev_*, stx_blksize.
These are local system information and are always available.
(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.
These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.
If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.
If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.
Note that there are instances where the type might not be valid, for
instance Windows reparse points.
(2) stx_rdev_*.
This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.
(3) stx_btime.
Similar to (1), except this will be set to 0 if it doesn't exist.
=======
TESTING
=======
The following test program can be used to test the statx system call:
samples/statx/test-statx.c
Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.
Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.
[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
Secondly, the result of automounting on that directory.
[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-02-01 00:46:22 +08:00
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|
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struct super_block *sb = path->dentry->d_sb;
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struct inode *inode = d_inode(path->dentry);
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generic_fillattr(inode, stat);
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if (INODE_VERSION(inode) == MINIX_V1)
|
2007-02-12 16:52:49 +08:00
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stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
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2005-04-17 06:20:36 +08:00
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|
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else
|
2007-02-12 16:52:49 +08:00
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|
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stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
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|
stat->blksize = sb->s_blocksize;
|
2005-04-17 06:20:36 +08:00
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|
return 0;
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|
}
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|
|
|
/*
|
|
|
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* The function that is called for file truncation.
|
|
|
|
*/
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|
|
|
void minix_truncate(struct inode * inode)
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|
|
|
{
|
|
|
|
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
|
|
|
|
return;
|
|
|
|
if (INODE_VERSION(inode) == MINIX_V1)
|
|
|
|
V1_minix_truncate(inode);
|
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|
else
|
|
|
|
V2_minix_truncate(inode);
|
|
|
|
}
|
|
|
|
|
2010-07-25 04:46:55 +08:00
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|
|
static struct dentry *minix_mount(struct file_system_type *fs_type,
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|
|
int flags, const char *dev_name, void *data)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2010-07-25 04:46:55 +08:00
|
|
|
return mount_bdev(fs_type, flags, dev_name, data, minix_fill_super);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
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|
|
|
|
|
|
|
static struct file_system_type minix_fs_type = {
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
.name = "minix",
|
2010-07-25 04:46:55 +08:00
|
|
|
.mount = minix_mount,
|
2005-04-17 06:20:36 +08:00
|
|
|
.kill_sb = kill_block_super,
|
|
|
|
.fs_flags = FS_REQUIRES_DEV,
|
|
|
|
};
|
2013-03-03 11:39:14 +08:00
|
|
|
MODULE_ALIAS_FS("minix");
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
static int __init init_minix_fs(void)
|
|
|
|
{
|
|
|
|
int err = init_inodecache();
|
|
|
|
if (err)
|
|
|
|
goto out1;
|
|
|
|
err = register_filesystem(&minix_fs_type);
|
|
|
|
if (err)
|
|
|
|
goto out;
|
|
|
|
return 0;
|
|
|
|
out:
|
|
|
|
destroy_inodecache();
|
|
|
|
out1:
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit exit_minix_fs(void)
|
|
|
|
{
|
|
|
|
unregister_filesystem(&minix_fs_type);
|
|
|
|
destroy_inodecache();
|
|
|
|
}
|
|
|
|
|
|
|
|
module_init(init_minix_fs)
|
|
|
|
module_exit(exit_minix_fs)
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
|